Metallic alloy



45 Manganese less than 4 Patented Oct. 4, 1932 UNITED STATES PATENT/OFFICE KOTARO HONDA AND TSUTOMU KASE, OF SENDAI, JAPAN, ASSIGNORS TO RESEARCH INSTITUTE FOR IRON, STEEL & OTHER METALS, OF SENDAI, JAPAN METALLIC ALLOY No Drawing. Application filed January 6, 1931, Serial No. 506,969, and in Japan August 20, 1930.

Our invention relates to an extremely hard netallic alloy containingtungsten or tantalum or both of them, chromium and molybdenum and/or vanadium as its main ingredients and 5 also a small amount of carbon, nickel and manganeseas sub-ingredients, and its object is to provide an important metallic alloy having an extraordinary high hardness-next to diamond and comparable with corundum and Widia (carboloy) at atmospheric temperature which is well adapted for use with glass cutting tools and the other cutting and abrasive tool as well as shaft journals.

A metallic alloyhaving the hardness comparable with corundum and nearly equal to that of diamond has heretofore never been produced artificially. In accordance with our invention we have obtained a metallic alloy having the highest hardness among me- .20 tallic alloys which have heretofore been known to the art. The metallic alloy of the invention consists of either one or both of tungsten or tantalum, chromium and molybdenum or vanadium as the main constituents and it may contain a small amount of carbon, nickel and manganese as sub-elements and is characterized in that the alloy proper has .a very high hardness without a special heat treatment.

In carrying out our invention into effect, the above mentioned main elements may be alloyed together at a suitable proportion to attain the object of the present invention and 5 the composition of the alloy may be taken, as

for example, as follows Example 1 Per cent ent.

Example 2 Per cent Tantalum 5 to 80 Tungsten 5 to 40 A small amount of impurities may be included as usually contained in the ingredients. It will be noted that in producing the metallic alloy of this invention the proportion of each ingredient may be suitably selected within the range as specified in the above examples and remarkably high hardness can be developed by alloying the main elements, that is, tungsten, molybdenum, and chromium While the similar object can be attained by replacing a part or Whole of tungsten with tantalum, and also by introducing a substantial amount of vanadium. The metallic alloy of this invention does not include tungstencarbide as the main element like Widia etc. which is known to the art, at pres- An alloy of this invention containing 42% of tungsten, 21% of molybdenum, 32% of chromium, 4.2% of nickel and 1.26% of carbon as another example has the hardness of 9 by the Mohs hardness scale so that it is equal to that of corundum. I

The metallic alloy-of this invention as it has extremely high hardness may be taken to form various tools by suitably finishing it with a specially prepared carborundum grinder and utilized as a glass cutter and other cutting and abrasive tools.

What We claim as new and desire to secure by Letters Patent of the United States, is:

1. A metallic alloy having a very high hardness containing as the main ingredients 30 to of tungsten, 20 to 50% of molybdenum and 30 to 50% of chromium and sub ingredients comprising carbon in an appreciable amount less than 2%, nickel in an appreciable amount less than 5% and manganese in an appreciable amount less than 4%.

2. A metallic alloy of a ver high hardness containing as the main ingre ients 30 to 50% of tungsten, 20 to 50% of molybdenum, 30 to 50% of chromium and as'sub-ingredients 0.10 to 0.7 5% of carbon, 0.10 to less than 5% of nickel, and 0.10 to less than 4% of manganese.

3. A metallic alloy of a very high hardness containing as the main ingredients 30 to 50% of tungsten, 20 to 50% of molybdenum, 30 to 50% of chromium and as sub-ingredients 0.10 to 0.75% of carbon, 0.1 to 3.5% nickel, and 0.1 to less than 4% of manganese.

4. A metallic alloy having a very high hardness containing in approximate proportions 42% of tungsten, 21% of molybdenum 27% of chromium, 4.2% of nickel, 1.26% o carbon and less than 4% of manganese.

In testimony whereof we have aifixed our signatures.

. KOTARO HONDA. TSUTOMU KASE. 

